Recently, with the improvement of people's living standard, more and more emphasis has been placed on outdoor recreational activities, some notable examples of which are cycling and mountain climbing. Take mountain climbing for instance. Many mountaineers would carry folding knives with them in case they need to cut or chop tree branches, thorns, and so forth on their way. Commercially available folding knives are composed essentially of a handle and a blade, wherein the blade is pivotally connected to the handle and is rotatable into and out of the handle. Once the blade of a folding knife is rotated out of the handle, the folding knife can be used for chopping or cutting. However, if the user exerts too much force or applies an oblique force to the folding knife while using it, the blade is very likely to fold automatically into the handle when subjected to the improperly applied force. This is very dangerous because the user's hand may end up being cut.
To solve the aforesaid safety problem, improvements have been made to the structure of folding knives. Please refer to FIG. 1 for a commonly seen example of such improved folding knives. The folding knife in FIG. 1 includes a handle 10, and the handle 10 is provided therein with a plate 100 formed with a resilient stopper 101. A blade 11 is pivotally connected to one side of the plate 100 and can be rotated into or out of the handle 10. When the blade 11 is received in the handle 10, the resilient stopper 101, which is resilient to a certain degree and extends toward the blade 11, presses resiliently against one side of the blade 11. Once the blade 11 is rotated out of the handle 10 (see FIG. 1), the resilient stopper 101 curves toward the blade 11, thanks to the resilience of the resilient stopper 101. As a result, the free end (i.e., the lower right end in FIG. 1) of the resilient stopper 101 moves to a position adjacent to one end of the blade 11 and presses against the blade 11. In FIG. 1, the lower right end of the resilient stopper 101 curves downward and presses against the upper left end of the blade 11.
When pressed against by the resilient stopper 101, the blade 11 cannot be folded easily into the handle 10. Even if the user tries to rotate the blade 11 into the handle 10, the resilient stopper 101 will prevent such rotation and keep the blade 11 from being folded. In order to fold the blade 11 properly, the user must push the resilient stopper 101 first, so the resilient stopper 101 is moved away from the position where it presses against the blade 11. Only then can the blade 11 be rotated. However, when the user holds the handle 10 and performs piercing or chopping actions with the folding knife 1, an excessively large force applied by the user or an improper chopping angle may subject the resilient stopper 101 to shocks or other forces that tend to drive the resilient stopper 101 away from the position where it presses against the blade 11. If that happens, the blade 11 may rotate toward the handle 10 instantly and cut the user's hand. It can be known from the above that neither the conventional nor the improved folding knife provides adequate safety in use.
Accordingly, the issue to be addressed by the present invention is to overcome the various drawbacks of the existing folding knives and design a folding knife whose blade is prevented from folding automatically. It is desirable that, once the blade is rotated out of the handle, the resilient stopper presses securely against the blade and yet still allows the user to fold the blade easily when needed, thus enhancing both the safety and convenience of the folding knife.